Analyzers to test liquid for specific ingredient concentration such as liquid hardness, oxygen dissolution, residual chlorine, suspended matter and the like are widely used. For instance, U.S. Pat. No. 7,333,194 B2 provides a portable photometric analysis which has a detachable housing with a lengthy seam to facilitate repair and maintenance. An extra waterproof element (such as a rubber pad) has to be provided and coupled to prevent liquid from permeating into the housing. This makes fabrication and assembly complicated and difficult during production or maintenance. Moreover, the handgrip of the housing does not provide pliable touch and give users undesirable grasp feeling when in use. Its hard and smooth surface even easily causes the instrument slipping from user's hand and results in dropping and damage of the portable photometric analysis.